1. Field of the Invention
This invention relates to dye compounds, and more particularly relates to a dye compound that can be used as a dye sensitizer in a dye-sensitized solar cell (DSSC), and to a DSSC using the dye compound as a dye sensitizer.
2. Description of the Related Art
The demand for carbon reduction has triggered the search for renewable energy sources, such as solar cells. Although Si-based semiconductors dominated solar cell applications for decades, recent development of DSSCs proves application of organic and organometallic dyes in this field. The DSSC is promising to be commercialized in the future, mainly because of its low cost, simple fabrication and high flexibility.
A DSSC can be formed by coating a porous film of nano-crystalline TiO2 on a conductive glass piece, adsorbing a dye on TiO2 and combining the resulting structure with a redox electrolytic solution and another conductive glass piece having a metal electrode thereon. When the dye molecule is excited by light, charge separation is induced therein, and an electric current is caused due to subsequent charge transfer to the electrolyte and TiO2.
When a ruthenium-based dye like N719 is used, the DSSC can have a conversion efficiency up to 11% at most. However, since such Ru-based dyes are very expensive, the study has turned to the application of non-metal dyes in DSSCs.